1. Field of the Invention
Aspects of the present invention relate to a computer system and a control method thereof which run processes of a plurality of programs being executed according to a priority order.
2. Description of the Related Art
The performance of a computer depends on a variety of factors, such as the running speed of a process, the life of a battery, noise, and so on. These factors, however, are mutually exclusive. For example, if the speed of a process increases, the life of the battery decreases and the noise of the computer system increases. Therefore, it is difficult to improve the running speed of the process, the life of the battery, the noise, etc., at the same time. Accordingly, it is preferable that factors are properly controlled depending on the circumstances, so that the computer may operate at optimal performance.
To improve the performance of a computer system, a conventional art (such as that described in Japanese patent first publication No. 07-0319569) discloses a way to convert a system operating environment, such as a power-saving mode, a high performance mode, and so on, through inputting a hot key by a system management interrupt (SMI). Though it is possible to change a mode in hardware, such as a CMOS memory, SMI, etc., it is impossible to do so in software, such as a priority control of an application thread or changing a power scheme which is applied by an Operating System (OS), in the conventional art.
In a typical Operating System (OS), such as Microsoft Windows, if a user wants to change a priority order of the application thread, i) the user pushes Ctrl+Alt+Del keys to run “Windows task manager”; ii) the user selects “select columns” in the “View” menu and selects “base priority” item in a dialog box; and iii) the user selects the process which the user wants and clicks the right mouse button. This procedure, which preferentially allocates a resource to a predetermined process, is very complicated. Accordingly, though an ordinary user may want to improve the running performance of a program, the user does not know how to do so. Thus, the user is not able to run the system at an optimal level of performance. Even if the user does know how to change the priority, the procedure is still cumbersome.